In-Lane Vector Shuffle Instructions

ABSTRACT

In-lane vector shuffle operations are described. In one embodiment a shuffle instruction specifies a field of per-lane control bits, a source operand and a destination operand, these operands having corresponding lanes, each lane divided into corresponding portions of multiple data elements. Sets of data elements are selected from corresponding portions of every lane of the source operand according to per-lane control bits. Elements of these sets are copied to specified fields in corresponding portions of every lane of the destination operand. Another embodiment of the shuffle instruction also specifies a second source operand, all operands having corresponding lanes divided into multiple data elements. A set selected according to per-lane control bits contains data elements from every lane portion of a first source operand and data elements from every corresponding lane portion of the second source operand. Set elements are copied to specified fields in every lane of the destination operand.

FIELD OF THE INVENTION

The invention relates to computer systems, and in particular, to an apparatus and method for performing multi-dimensional computations using an in-lane shuffle operation.

BACKGROUND

A Single Instruction, Multiple Data (SIMD) architecture improves efficiency of multi-dimensional computations. Implemented in computer systems, the SIMD architecture enables one instruction to operate on data simultaneously, rather than on a single data. In particular, SIMD architectures take advantage of packing many data elements within one register or memory location. With parallel hardware execution, multiple operations can be performed with one instruction, resulting in significant performance improvement.

Although many applications currently in use can take advantage of such operations, known as vertical operations, there are a number of important applications which require the rearrangement of the data elements before vertical operations can be implemented so as to provide realization of the application. Examples of some important applications include the dot product and matrix multiplication operations, which are commonly used in 3-D graphics and signal processing applications.

One problem with rearranging the order of data elements within a register or memory word is the mechanism used to indicate how the data should be rearranged. Typically, a mask or control word is used. The control word must include enough bits to indicate which of the source data fields must be moved into each destination data field. For example, if a source operand has eight data fields, requiring three bits to designate any given data field, and the destination register has four data fields, (3×4) or 12 bits are required for the control word. However, on a processor implementation where there are less than 12 bits available for the control register, a full shuffle cannot be supported. Some approaches addressing such issues were presented, for example, in U.S. Pat. No. 6,041,404 and in U.S. Pat. No. 7,155,601.

The problem described above is made worse though, when even more data fields are permitted in the sources and destinations. Moreover the complexity of circuitry required to shuffle data and to control said shuffling can increase proportional to the square of the number of permitted data fields causing undesirable delays, costing precious die area, and consuming ever more power. Therefore, there is a need for a way to reorganize the order of data elements where less than the full number of bits is available for a control register in such a way as to scale to handle operands where even more data fields are permitted.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:

FIG. 1 illustrates an exemplary computer system in accordance with one embodiment of the invention;

FIGS. 2 a to 2 c illustrate flow diagrams for processes to perform shuffle instructions according to a set of embodiments of the invention;

FIGS. 3 a to 3 b illustrate flow diagrams for processes to perform shuffle instructions according to a set of alternative embodiments of the invention;

FIG. 4 illustrates an example of a field of per-lane control bits;

FIGS. 5 a to 5 c illustrate the operation of the shuffle instructions in accordance with embodiments of the invention.

FIGS. 6 a to 6 b illustrate the operation of the shuffle instructions in accordance with alternative embodiments of the invention.

DETAILED DESCRIPTION

In-lane vector shuffle operations are described herein. In embodiments of a shuffle operation, sets of data elements are selected from corresponding portions of each lane of a source operand according to per-lane control bits and copied to specified fields in corresponding portions of each lane of a destination operand. Other embodiments of the shuffle instruction specify two source operands, all operands having corresponding lanes divided into multiple data elements. Data elements selected according to per-lane control bits include data elements from each lane portion of a first source operand and include data elements from each corresponding lane portion of a second source operand, which are copied to specified fields in corresponding lanes of the destination operand.

The shuffle instruction has useful applications in data reorganization and in moving data into different locations of the register to allow, for example, extra storage for scalar operations, manipulation of complex numbers that require transforms, or to facilitate conversion between data formats such as from packed integer to packed floating point and vice versa. Such application in the technical arts include but are not limited to motion video compression/decompression, image filtering, audio signal compression, filtering or synthesis, modulation/demodulation, etc. Data formats of certain particular data or signal types such as audio or motion video for example, which are representative of or constitute communication, physical activity or objects often have regular structures and component data elements which can be manipulated or transformed in substantially similar ways for each lane of a source operand. Thus shuffling data elements according to a field of per-lane control bits is applicable to such data or signal types.

In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it will be understood by one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the invention.

FIG. 1 illustrates one of many embodiments of a computer system 100 which implements the principles of the present invention. Computer system 100 comprises a processor 105, a storage device 110, and a bus 115. The processor 105 is coupled to the storage device 110 by the bus 115. In addition, a number of user input/output devices 120, such as a keyboard, mouse and display, are also coupled to the bus 115.

The processor 105 represents a central processing unit of any type of architecture, such as Complex Instruction Set Computer (CISC), Reduced Instruction Set Computer (RISC), very long instruction word (VLIW), or a hybrid architecture (e.g., a combination of hardware and software translation). Also, the processor 105 could be implemented on one or more chips. The storage device 110 represents one or more mechanisms for storing data. For example, the storage device 110 may include read only memory (ROM), random access memory (RAM), magnetic disk storage mediums, optical storage mediums, flash memory devices, and/or other machine-readable mediums. The bus 115 represents one or more buses (e.g., Accelerated Graphics Port “AGP”, Peripheral Component Interconnect “PCI”, Industry Standard Architecture “ISA”, Extended Industry Standard Architecture “EISA”, Video Electronics Standard Architecture “VESA” and the like) and bridges (also termed as bus controllers). While this embodiment is described in relation to a single processor computer system, the invention could be implemented in a multi-processor computer system.

In addition, while embodiments of the invention are herein described in relation to 256-bit operands having 128-bit lanes, the invention is not limited to a computer system with 128-bit lanes or 256-bit operands. For example, lanes could be comprised of but not limited to having 64 bits, and operands could independently be comprised of but not limited to having 512 bits.

Furthermore, devices including but not limited to one or more of a network 130, a TV broadcast signal receiver 131, a fax/modem 132, a digitizing unit 133, a sound unit 134, and a graphics unit 135 may optionally be coupled to bus 115. The network 130 represents one or more network connections (e.g., an Ethernet connection). The TV broadcast signal receiver 131 represents a device for receiving TV broadcast signals, the fax/modem 132 represents a fax and/or modem for receiving and/or transmitting analog signals. The digitizing unit 133 represents one or more devices for digitizing images (e.g., a scanner, camera, etc.). The sound unit 134 represents one or more devices for inputting and/or outputting sound (e.g., sound card, microphones, speakers, magnetic storage devices, optical storage devices, etc.). The graphics unit 135 represents one or more devices for generating images (e.g., graphics card).

FIG. 1 also illustrates that the storage device 110 has stored therein data 140 and software 145. Data 140 represents data stored in one or more of the formats described herein. Software 145 represents the necessary code for performing any and/or all of the techniques in accordance with the present invention. It will be recognized by one of ordinary skill in the art that the storage device 110 may contain additional software (not shown), which is not necessary to understanding the invention.

FIG. 1 additionally illustrates that the processor 105 includes decode unit 150, a set of registers 151, execution unit 152, and an internal bus 153 for executing instructions. It will be recognized by one of ordinary skill in the art that the processor 105 contains additional circuitry, which is not necessary to understanding the invention. The decode unit 150, registers 151 and execution unit 152 are coupled together by internal bus 153. The decode unit 150 is used for decoding instructions received by processor 105 into control signals and/or microcode entry points. In response to these control signals and/or microcode entry points, the execution unit 152 performs the appropriate operations. The decode unit 150 may be implemented using any number of different mechanisms (e.g., a look-up table, a hardware implementation, a programmable logic array “PLA”). Any mechanism for logically performing decoding of the various instructions is considered to be within the scope of the implementation of the invention.

The decode unit 150 is shown including a packed data instruction set 160 for performing operations on packed data. In one possible embodiment, the packed data instruction set 160 includes the shuffle instruction(s) 164 for performing in-lane vector shuffle operations. The number format for the instructions can be any formant including signed and unsigned integers, floating-point numbers, and non-numeric data. The operations of these shuffle instructions are briefly described below and in greater detail with regard to FIGS. 2 a-2 c, 3 a-3 b, 5 a-5 c and 6 a-6 b.

One embodiment includes shuffling packed data elements according to a single shuffle instruction 164 that specifies a field of per-lane control bits, a single source operand and a destination operand. The source and destination operands each have corresponding multi-bit lanes that may be divided into upper and lower portions, each including a similar number of data elements. According to the field of per-lane control bits, a substantially similar set of data elements can be selected from any data elements in corresponding portions of every multi-bit lane of the source operand. Then each data element of the selected set can be copied, according to the field of per-lane control bits, to any specified data fields located in corresponding portions of every multi-bit lane of the destination operand.

Alternatively a single shuffle instruction 164 specifies the field of per-lane control bits, a first source operand, a second source operand, and a destination operand, all operands having corresponding multi-bit lanes, the corresponding multi-bit lanes having corresponding portions, each including a substantially similar number of data elements. Again, using a field of per-lane control bits, a set of data elements can be selected including data elements from every multi-bit lane portion of the first source operand and including data elements from every corresponding multi-bit lane portion of the second source operand. Each data element of the selected set can then be copied to specified locations in corresponding multi-bit lanes of the destination operand.

In addition to the packed data instructions, processor 105 can include new instructions and/or instructions similar to or the same as those found in existing general purpose processors. For example, in one embodiment, the processor 105 supports an instruction set which is compatible with the Intel® Architecture instruction set used in the Pentium® processors and/or Core™ processors.

It will be appreciated that as in some instructions of the Intel® Architecture instruction set and in some embodiments of shuffle instruction 164, a source operand and a destination operand as described herein may, in fact, be the same operand and source data may be overwritten by destination data in that operand. Alternative embodiments of the invention may contain more or less, as well as different, packed data instructions and still utilize the teachings of the invention.

The registers 151 represent a storage area on processor 105 for storing information, including control/status information, integer data, floating point data, and packed data. It will be understood by one of ordinary skill in the art that one aspect of the invention is the described instruction set for operating on packed data as well as how the instructions are used. According to these aspects of the invention, the storage area used for storing the packed data is not critical. The term data processing system is used herein to refer to any machine for processing data, including the computer systems(s) described with reference to FIG. 1.

While one embodiment of the invention is described below with regard to FIGS. 5 b-5 c, in which the processor 105, executing the packed data instructions operates on 256-bit packed data operands containing sixteen 16-bit packed data elements called “words,” the processor 105 can operate on packed data in several different packed data formats. For example, in one embodiment, packed data can be operated on a “byte” format or a “double word” (dword) format. The packed byte format includes thirty-two separate 8-bit data elements and the packed dword format includes eight separate 32-bit data elements, for example as shown in FIG. 5 a. While certain instructions are discussed below with reference to integer data, the instructions may be applied to other packed data formats as well. The 32-bit data elements shown in FIG. 5 a or as shown in FIG. 6 b may represent packed single-precision floating-point data, for example, and 64-bit data elements shown in FIG. 6 a may be understood to represent packed double-precision floating-point data.

FIG. 2 a illustrates a flow diagram for one embodiment of a process to perform a shuffle instruction 164 according to one embodiment of the invention. In this embodiment, the shuffle instruction 164. Process 201 and other processes herein disclosed are performed by processing blocks that may comprise dedicated hardware or software or firmware operation codes executable by general purpose machines or by special purpose machines or by a combination of both.

This embodiment includes shuffling packed data elements according to a single shuffle instruction 164 that specifies a field of per-lane control bits 7-0, a single source operand and a destination operand. The source operand is accessed in processing block 220. The source and destination operands each have corresponding multi-bit lanes. For one embodiment these multi-bit lanes are each 128-bit lanes each including a similar number of (e.g. in this case four) data elements. According to the field of per-lane control bits 7-0 and the VSHUFD shuffle instruction 164 of processing block 225, a substantially similar set of data elements is selected from any data elements D-A and from any data elements H-E in each 128-bit lane of the source operand. Then in processing block 229 each data element of the selected set is copied, according to the field of per-lane control bits 7-0, to any data fields located in corresponding portions of each 128-bit lane of the destination operand as specified according to the VSHUFD shuffle instruction 164.

FIG. 2 b illustrates a flow diagram for one embodiment of a process 202 to perform a shuffle instruction 164 according to an alternative embodiment of the invention. This embodiment includes shuffling packed data elements according to a single shuffle instruction 164 that again specifies a field of per-lane control bits 7-0, a single source operand and a destination operand. The source operand is accessed in processing block 240. The source and destination operands each have corresponding multi-bit lanes. For example, in this case these multi-bit lanes are each 128-bit lanes that may be divided into upper and lower portions, each including a similar number of (e.g. in this case four) data elements. According to the field of per-lane control bits 7-0 and the VSHUFLW shuffle instruction 164 of processing block 245, a substantially similar set of data elements is selected from any data elements D-A and from any data elements H-E in corresponding lower portions of each 128-bit lane of the source operand. Then in processing block 249 each data element of the selected set is copied, according to the field of per-lane control bits 7-0, to any data fields located in corresponding portions of each 128-bit lane of the destination operand as specified according to the VSHUFLW shuffle instruction 164. The higher portions of each 128-bit lane of the source operand (in this case bits 255-192 and bits 127-64) are copied to corresponding higher portions of each 128-bit lane of the destination operand.

FIG. 2 c illustrates a flow diagram for one embodiment of a process 203 to perform a shuffle instruction 164 according to another alternative embodiment of the invention. This embodiment includes shuffling packed data elements according to a single shuffle instruction 164 that also specifies a field of per-lane control bits 7-0, a single source operand and a destination operand. The source operand is accessed in processing block 250. Again the source and destination operands each have corresponding multi-bit lanes, which are both 128-bit lanes in this case, that may be divided into upper and lower portions, each including a similar number (e.g. four) of data elements. According to the field of per-lane control bits 7-0 and the VSHUFHW shuffle instruction 164 of processing block 255, a substantially similar set of data elements is selected from any data elements D-A and from any data elements H-E in corresponding higher portions of each 128-bit lane of the source operand. Then in processing block 259 each data element of the selected set is copied, according to the field of per-lane control bits 7-0, to any data fields located in corresponding portions of each 128-bit lane of the destination operand as specified according to the VSHUFHW shuffle instruction 164. The lower portions of each 128-bit lane of the source operand (in this case bits 191-128 and bits 63-0) are copied to corresponding lower portions of each 128-bit lane of the destination operand.

FIG. 3 a illustrates a flow diagram for one embodiment of a process 301 to perform a shuffle instruction 164 according to another alternative embodiment of the invention. This embodiment includes shuffling packed data elements according to a single shuffle instruction 164 that specifies a field of per-lane control bits 3-2 and bits 1-0, a first source operand, a second source operand, and a destination operand. The first source operand, S, is accessed in processing block 380A. The second source operand, S2, is accessed in processing block 380B. All operands have corresponding multi-bit lanes, which are 128-bit lanes in this case, each multi-bit lane includes a substantially similar number (e.g. two) of data elements. According to the field of per-lane control bits 3-2, bits 1-0 and the VSHUFPD shuffle instruction 164 of processing block 385, a set of data elements can be selected including data elements (X1 or X2 and X3 or X4) from the 128-bit lanes of the first source operand and data elements (Y1 or Y2 and Y3 or Y4) from the 128-bit lanes of the second source operand. Then in processing block 389 each data element of the selected set is copied to locations in corresponding 128-bit lanes of the destination operand as specified according to the VSHUFPD shuffle instruction 164.

FIG. 3 b illustrates a flow diagram for one embodiment of a process 302 to perform a shuffle instruction 164 according to another alternative embodiment of the invention. This embodiment includes shuffling packed data elements according to a single shuffle instruction 164 that specifies a field of per-lane control bits 7-0, a first source operand, a second source operand, and a destination operand. The first source operand, S, is accessed in processing block 390A. The second source operand, S2, is accessed in processing block 390B. All operands have corresponding multi-bit lanes, which are 128-bit lanes in this case, each multi-bit lane includes a substantially similar number (e.g. four) of data elements. According to the single field of per-lane control bits 7-0 and the VSHUFPS shuffle instruction 164 of processing block 395, a set of data elements can be selected including corresponding data elements (X1-X4 or X5-X8) from every 128-bit lane of the first source operand and including corresponding data elements (Y1-Y4 or Y5-Y8) from every 128-bit lane of the second source operand. Then in processing block 399 each data element of the selected set is copied to locations in corresponding 128-bit lanes of the destination operand as specified according to the VSHUFPS shuffle instruction 164.

FIG. 4 illustrates an example of a control word, imm8, to specify a field of per-lane control bits up to bits 7-0. As described above, embodiments of shuffle instruction 164 may specify a field of per-lane control bits, one or more source operands, and a destination operand, wherein the field of per-lane control bits is specified by a portion of an 8-bit immediate operand, imm8. It will be appreciated that by specifying the field of per-lane control bits as described a longer control word is not needed to handle operands where more data fields are permitted. Therefore decoding hardware may be less complex and hence faster, and the sizes of execution units may be more proportional to the number of data fields that are permitted rather than to the square of that number.

FIG. 5 a illustrates the operation of the shuffle instruction 164 in accordance with an embodiment of the invention. This embodiment includes shuffling packed data elements in an execution unit 152 responsive to the decoding, in decode unit 150, of a single shuffle instruction 164 that specifies a field of per-lane control bits 7-0, a single source operand 520 and a destination operand 529. Source operand 520 and destination operand 529 each have corresponding multi-bit lanes. For one embodiment the multi-bit lanes are all 128-bit lanes each including a similar number of (e.g. in this case four) data elements.

Responsive to the decoding of the VSHUFD shuffle instruction 164 a substantially similar set of data elements is selected from any data elements D-A by the 4:1 multiplexers 424-421 and from any data elements H-E by the 4:1 multiplexers 528-525 in each 128-bit lane of source operand 520 according to the field of per-lane control bits 7-0. Using the outputs of the 4:1 multiplexers 524-521 and the 4:1 multiplexers 528-525, data elements of the selected set are copied to any of the data fields located in corresponding 128-bit lanes of the destination operand 529 as specified according to the VSHUFD shuffle instruction 164 and the field of per-lane control bits 7-0.

FIG. 5 b illustrates the operation of the shuffle instruction 164 in accordance with an alternative embodiment of the invention. This embodiment includes shuffling packed data elements in an execution unit 152 responsive to the decoding, in decode unit 150, of a single shuffle instruction 164 that again specifies a field of per-lane control bits 7-0, a single source operand 540 and a destination operand 549. The source operand 540 and destination operand 549 each have corresponding multi-bit lanes. For example, in this case these multi-bit lanes are each 128-bit lanes that may be further divided into upper portions (e.g. bits 255-192 and 127-64) and lower portions (e.g. bits 191-128 and 63-0), each including a similar number of (e.g. in this case four) data elements.

Responsive to the decoding of the VSHUFLW shuffle instruction 164 a substantially similar set of data elements is selected from any data elements D-A by the 4:1 multiplexers 544-541 and from any data elements H-E by the 4:1 multiplexers 548-545 in corresponding lower portions of each 128-bit lane of source operand 540 according to the field of per-lane control bits 7-0. Using the outputs of the 4:1 multiplexers 544-541 and the 4:1 multiplexers 548-545, data elements of the selected set are copied to any of the data fields located in corresponding lower portions of each 128-bit lane of the destination operand 549 as specified according to the VSHUFLW shuffle instruction 164 and the field of per-lane control bits 7-0. The higher portions of each 128-bit lane of source operand 540 (e.g. bits 255-192 and 127-64) are copied to corresponding higher portions of each 128-bit lane of destination operand 549.

FIG. 5 c illustrates the operation of the shuffle instruction 164 in accordance with another alternative embodiment of the invention. This embodiment includes shuffling packed data elements in an execution unit 152 responsive to the decoding, in decode unit 150, of a single shuffle instruction 164 that also specifies a field of per-lane control bits 7-0, a single source operand 550 and a destination operand 559. The source operand 550 and destination operand 559 each have corresponding multi-bit lanes. For example, in this case these multi-bit lanes are each 128-bit lanes that may be further divided into upper portions (e.g. bits 255-192 and 127-64) and lower portions (e.g. bits 191-128 and 63-0), each including a similar number of (e.g. four) data elements.

Responsive to the decoding of the VSHUFHW shuffle instruction 164 a substantially similar set of data elements is selected from any data elements D-A by the 4:1 multiplexers 554-551 and from any data elements H-E by the 4:1 multiplexers 558-555 in corresponding higher portions of each 128-bit lane of source operand 550 according to the field of per-lane control bits 7-0. Using the outputs of the 4:1 multiplexers 554-551 and the 4:1 multiplexers 558-555, data elements of the selected set are copied to any of the data fields located in corresponding higher portions of each 128-bit lane of the destination operand 559 as specified according to the VSHUFHW shuffle instruction 164 and the field of per-lane control bits 7-0. The lower portions of each 128-bit lane of source operand 550 (e.g. bits 191-128 and 63-0) are copied to corresponding lower portions of each 128-bit lane of destination operand 559.

FIG. 6 a illustrates the operation of the shuffle instruction 164 in accordance with another alternative embodiment of the invention. This embodiment includes shuffling packed data elements in an execution unit 152 responsive to the decoding, in decode unit 150, of a single shuffle instruction 164 that specifies a field of per-lane control bits 3-2 and bits 1-0, a first source operand 680A, a second source operand 680B, and a destination operand 689. First source operand 680A, second source operand 680B, and destination operand 689 all have corresponding multi-bit lanes, which are 128-bit lanes in this case, each multi-bit lane includes a substantially similar number (e.g. two) of data elements.

Responsive to the decoding of the VSHUFPD shuffle instruction 164 a set of data elements can be selected including corresponding data elements (X1 or X2 and X3 or X4) from every 128-bit lane of first source operand 680A by the 2:1 multiplexers 683 and 681 and including corresponding data elements (Y1 or Y2 and Y3 or Y4) from every 128-bit lane of second source operand 680B by the 2:1 multiplexers 684 and 682 according to the field of per-lane control bits 3-2 and bits 1-0. Using the outputs of the 2:1 multiplexers 684-681 data elements of the selected set are copied to locations in corresponding 128-bit lanes of the destination operand 689 as specified according to the VSHUFPD shuffle instruction 164 and the field of per-lane control bits 3-2 and bits 1-0.

FIG. 6 b illustrates the operation of the shuffle instruction 164 in accordance with another alternative embodiment of the invention. This embodiment includes shuffling packed data elements in an execution unit 152 responsive to the decoding, in decode unit 150, of a single shuffle instruction 164 that specifies a single field of per-lane control bits bits 7-0, a first source operand 690A, a second source operand 690B, and a destination operand 699. First source operand 690A, second source operand 690B, and destination operand 699 all have corresponding multi-bit lanes, which are 128-bit lanes in this case, each multi-bit lane includes a substantially similar number (e.g. four) of data elements.

Responsive to the decoding of the VSHUFPS shuffle instruction 164 a set of data elements can be selected including corresponding data elements (X1-X4 or X5-X8) from every 128-bit lane of first source operand 690A by the 4:1 multiplexers 691-692 and 695-696 and including corresponding data elements (Y1-Y4 or Y5-Y8) from every 128-bit lane of second source operand 690B by the 4:1 multiplexers 693-694 and 697-698 according to the field of per-lane control bits 7-0. Using the outputs of the 4:1 multiplexers 698-691 data elements of the selected set are copied to locations in corresponding 128-bit lanes of the destination operand 689 as specified according to the VSHUFPS shuffle instruction 164 and the field of per-lane control bits 7-0.

The above description is intended to illustrate preferred embodiments of the present invention. From the discussion above it should also be apparent that especially in such an area of technology, where growth is fast and further advancements are not easily foreseen, the invention may be modified in arrangement and detail by those skilled in the art without departing from the principles of the present invention within the scope of the accompanying claims and their equivalents. 

What is claimed is:
 1. A computer implemented method for shuffling packed data elements comprising: decoding a single instruction specifying a single field of per-lane control bits, and indicating a source operand and a destination operand, said source and destination operands having corresponding pluralities of multi-bit lanes, each multi-bit lane being divided into corresponding pluralities of portions, each of said corresponding portions including a same plurality of data elements; responsive to decoding the single instruction and the single field of per-lane control bits, selecting a set of data elements from any data elements in corresponding portions of every multi-bit lane of the source operand using the single field of the per-lane control bits for each of the multi-bit lanes; and copying the selected sets of data elements to the corresponding portions of every multi-bit lane of the destination operand.
 2. The method of claim 1, wherein the corresponding portions are either upper halves or lower halves of each of said plurality of multi-bit lanes of the source and destination operands.
 3. The method of claim 2, wherein the multi-bit lanes are 128-bit lanes.
 4. The method of claim 2, wherein the data elements are 16-bit data elements.
 5. The method of claim 1, wherein the source operand and the destination operand are a same operand.
 6. The method of claim 1, wherein said source and destination operands are 256-bit operands.
 7. A processor comprising: a plurality of registers; a decode unit to decode a single instruction specifying per-lane control bits, and indicating a source operand and a destination operand, said source and destination operands having corresponding pluralities of multi-bit lanes, each multi-bit lane being divided into corresponding pluralities of portions, each of said corresponding portions including a plurality of data elements; an execution unit including hardware, responsive to said decoding of the single instruction and the per-lane control bits, to select a set of data elements from any data elements in corresponding portions of every multi-bit lane of the source operand using the per-lane control bits for each of the multi-bit lanes, and to copy the selected sets of data elements to corresponding portions of every multi-bit lane of the destination operand.
 8. The processor of claim 7, wherein the corresponding portions are either upper halves or lower halves of each of said plurality of multi-bit lanes of the source and destination operands.
 9. The processor of claim 7, wherein the multi-bit lanes are 128-bit lanes.
 10. The processor of claim 9, wherein the data elements are 16-bit data elements.
 11. The processor of claim 10, wherein the source operand and the destination operand are a same operand.
 12. The processor of claim 10, wherein said source and destination operands are 256-bit operands.
 13. A processor comprising: a decode unit to decode a single instruction indicating per-lane control bits, a source operand, and a destination operand, the source operand and the destination operand each having first and second lanes; and an execution unit including hardware, the execution unit based on the decoding of the single instruction to shuffle data elements from the first lane of the source operand to the first lane of the destination operand according to the per-lane control bits and to shuffle data elements from the second lane of the source operand to the second lane of the destination operand according to the per-lane control bits, wherein a same plurality of bits of the per-lane control bits is used to shuffle both a first data element of the first lane of the source operand to the destination operand and also a second data element of the second lane of the source operand to the destination operand, the first data element and the second data element in same relative positions in the first and second lanes of the source operand.
 14. The apparatus of claim 13, wherein the execution unit is to shuffle any data elements from the first lane of the source operand to the first lane of the destination operand.
 15. The apparatus of claim 13, wherein the execution unit is to shuffle from among only half of data elements from the first lane of the source operand to the first lane of the destination operand.
 16. The apparatus of claim 13, wherein a lowest order two bits of the per-lane control bits are used for a lowest order data element in a first lane of the destination operand, and the lowest order two bits of the per-lane control bits are used for a lowest order data element in a second lane of the destination operand. 